2 questions about bike maintainence
 

Hi,

My bike is an entry level specialized vita that is 9 years old. I typically ride about 2000 to 2500 miles a year between commuting to work and joy riding and local touring weekends.

I was told by my lbs that I need to replace my front wheel due to the bike rim being worn because the bike is 9 years old and the rim has a lot of wear. Is this a valid concern?

Also when replacing the rear cassette and chain how necessary is replacing the front chain-ring in making the drive-train run correctly, as the front chain-ring has not been changed in the 9 years I have owned the bike. My lbs is suggesting I do this. I want the bike to run as smooth as possible.

Let me say that I was in my lbs and asked them to change a flat tire and use the same brand and model tire I currently had on the bike. The mechanic said they did not have that particular tire. So he showed me another tire that was cheaper and I told him he could use it. While he was changing the the flat tire, I went and looked in the showroom and found the same tire that was on my bike. When I brought it back to show him and ask him if it was the one that was originally on my bike he said yes. I asked him to change out the two he had put on that were cheaper and give me the new but same tire brand and model that was originally on the bike and he did the work. I find it hard to believe that I could find the brand and model that I originally had and the mechanic could not. It makes me not trust him or the shop. That is why I am here asking the questions about what I was told at the lbs.

Thank-you in advance for any and all help.

.
...this sort of question comes up regularly here in the mechanics forum. There's no good answer.

Failure to find the tyre you found does not immediately mean the mechanic you talked to is either incompetent or untrustworthy.
Rims do wear out on the sidewalls after enough braking wear from the brake shoes, depending on conditions. When they get thin enough along the brake track, they can fail.
Chain rings do wear out, depending on how dirty your chain gets, your conditions, and how often you change the chain. If you ride regularly in the smaller ring, that's where you see the wear.

Neither of these problems is diagnosable over the internet, without some fairly detailed pictures.

IN general, there is a lot more worry and anxiety over getting ripped off by a mechanic than is warranted by the frequency of ripoffs. But I understand your concern. No one likes to be taken advantage of.

Why are you buying a tire just to fix a flat?

3 alarmer, thank-you for answering my question. I am not really looking for diagnosis just if those are real valid issues. If they were I will have them fixed. But when I told a car mechanic that I trust( weird I know, but he is my brother). He did not seem to think they were problems that happened with bikes. I know can go show him yes they are.

Anklework, the reason for buying tires to fix a flat is the tires are a few years old and the mechanic was showing me the wear on the tires. Whether real or imagined wear, i changed both tires as I felt the tires were old enough and could use a new tire. I also got a new tube on the tire that was flat but re-used the tube on the tire that was not flat.

The mechanic might have been a "back room" guy and not totally aware of their inventory. Simple ignorance vs malice.

Sometimes, the factory tires aren't the best tires for your specific use.
If you only ride on smooth pavement, a slightly smaller slick tire would roll easier and make the bike accelerate easier/quicker.
The Specialized Armadillo tires on my Globe were horrible. Their rolling resistance wasn't much better than knobbys.

Nine years, at 2k miles (including the conditions of urban commuting) will cause normal wear to your rim's braking surface, the drivetrain (chainrings, chain, cassette), and tires. I'd say all those parts were due to be replaced. As for finding the original equipment tires, that's not a big deal. People often change out parts (including tires) to dial in the ride (eg, different stem length, bar widths, tires). I wouldn't be wary of this shop/mechanic based on the info provided.

A little looking into the topic of "drivetrain wear" might be helpful. Start here: Sheldon Brown.
Sprockets will last a lot longer if the chain is replaced in a timely manner. See THIS. The smallest sprockets wear fastest, all else being equal, and the chainrings are generally the last to need replacement unless drivetrain mainteneance has been sorely neglected.

Yes. Caliper brake wear on aluminum rims happens. If you don't replace the rim it can crack and the tire blow out. Modern rims have a "wear indicator" machined into the brake track. When the indicator disappears it's time to replace.

Years ago I had a well-worn rim explode as I was riding along. Fortunately I was riding at a mellow pace on a bike path. Still, I had to wait a couple hours for my wife to ride home and fetch the van.

https://cimg4.ibsrv.net/gimg/bikefor...2edf304acd.jpg
https://cimg6.ibsrv.net/gimg/bikefor...a2ca6c4f13.jpg

I can verify this, as it's (nearly) happened to me several times on my commuter bike. Luckily, before the rim disintegrates it begins to expand in width at the weakest point and a distinct "thump" happens when the brake is applied. Close inspection will reveal the source of the thump, and immediate rim replacement is indicated.
In my experience, this always happens on the rear wheel... for reasons I don't fully understand, because I use the front brake more heavily than the rear. It certainly could happen on a front rim though.

https://cimg0.ibsrv.net/gimg/bikefor...f3144ef35e.jpg
Imminent rim separation; lateral view


https://cimg1.ibsrv.net/gimg/bikefor...6306ce9435.jpg
Imminent rim separation; radial view... THUMP!


https://cimg5.ibsrv.net/gimg/bikefor...db46f2600c.jpg
Can't say I wasn't warned!

Anything is possible. A few closeup pictures of the suspect parts posted to the forums will do more than guesses.

thank-you sweeks, and jeffwillis, for the information about rim wear. I was thinking that it was a true thing but when I mentioned it to my mechanic brother he thought that it was not an issue I would have to worry about. I can now show him this thread and he can see for himself it is a very real concern. And not one I should take lightly.

Also sweeks thank-you for the information on the drive-train. It is very informative.

​​​​​​I appreciate everyone's information.

1. Feel your front rim's brake surface with your finger. If it feels noticeably convex it's time for a new one.
2. New chainrings are rounded at the tops of the teeth. If yours look pointy, it's time for a replacement.

Age and miles ridden are poor predictors for either.

If a rear rim splits you might be lucky and be able to ride it for a bit maybe enough to get home. I had that happen to me 15 miles from home but was able to ride the bike home SLOWLY as the wheel felt way out of true. On a front wheel? I think a failed rim could well be catastrophic.

Cheers

I don't think I would want to ride a rim that has been subjected to caliper brakes for 18,000 to 22,500 miles. He's not wrong. Both wheels are probably due for replacement. Great time to upgrade.

Unless you are trying to restore a bike to original, there's no reason to stick with the same brand and model of tires that came stock with the bike. If you are riding 2000 to 2500 miles a year, you deserve some nice tires instead of the tires that the manufacturer had a good deal on.

For me, chains start getting old in the 1000 to 1500 mile range. Cassettes in the 4000-5000 mile range. And I've never changed chainrings, though I'd love to get a higher-end chainset on both of my bikes, and probably ought to use mileage as a motivation to do so. :)

Ask him if he ever replaced a brake rotor on a vehicle. Same thing, the rim is basically a brake rotor.

Rim wear is not a thing you can base on miles/years, much more about conditions ridden in and maintenance performed.
People urban riding in wet weather and gritty roads (think PNW) will wear through rims on a regular basis, while others in dry conditions and little reason to brake will outlive a rim. Keeping rims and pads clean, especially after riding in rain, will add to rim longevity. I've never replaced a rim due to wear, but I don't normally ride in conditions that accelerate wear and regularly clean them, nor do I live in a location that has those conditions.

Chain rings are similar to rims in that they normally have a long life given some routine maintenance of the overall drivetrain. Smaller rings will wear faster than bigger rings due to the load being spread over a shorter distance on the ring.

The question I have is whether the rear rim has ever been replaced. Generally speaking, rear rims wear many time quicker than fronts. Most people use their rear brake more often than the front, and the rear wheel is subject to road dirt and grit thrown up by the front tire towards the bottom bracket and rear wheel. I have worn out several rear rims riding in wet and dirty road conditions during the 25 years that I was a 8,000 km per year bike commuter. I once wore out a front hub, but the rim was still in pretty good condition

the rear wheel was replaced a few years ago. I do not remember why it was done but it was replaced.

I know he has replaced brake rotors as I have watched him do them on my vehicles in the past.

I purchased a new wheel and it was put on the bike Sunday afternoon. I was not riding on that wheel after what I read on this thread.

I am not trying to restore the bike to original. I have upgraded the tires to a brand and model that was recommended to me by the lbs and I love them.
I have also changed the chain and cassette at least twice over the last 9 years. I try and do the maintainence to keep the bike running nice.

It's impossible to tell for sure without seeing it, but after 20K miles it is very likely that at least one of the chainrings need replacement (if it's not the riveted type - then replacement of the whole crankset would be in order). Even if it's not as badly worn as to cause chain skip, it might cause chain suck (chainlinks not properly disengaging from chainring teeth thus the chain wraps back up the chainring) which in turn can cause serious damage to rear derailleur.

Regarding the tire situation, I don't think the mechanic was trying to rip you off, since he suggested a cheaper tire, not a more expensive one.

Nothing about the shop's actions or recommendations seems suspect to me.

Chains need replacing the most often, cassettes less so, and cranksets much less so. Maybe 4 chains for every 2 cassettes and 1 set of chainrings, likely less chainring changes than that. This is assuming you're replacing the chain often and early when worn--you can blow through all three pretty easily if you just ride it into the ground. That said, with the mileage and time you've had the bike chainring replacements may likely be required and will almost certainly shift better. Given the relatively entry level nature of your bike, new chainrings (or often a new crankset--it's sometimes cheaper than new rings weirdly enough) of similar quality would be a pretty reasonable investment given the admirable amount of riding you do.

Your mechanic is likely recommending a sane course of action that DEFINITELY will work well. If you'd like, you can ask them to install a new chain and cassette and see if the chain skips on any of the old chainrings or shifts poorly, but given the mileage you have all new would be totally sensible without any testing.

Failing to find a tire isn't really a sign of trustworthiness or mechanical competence, it's really easy to miss things like that.

My viewpoint is informed but really biased as a professional mechanic. I have nearly never seen mechanics recommend needless service or try to rip customers off. A sign of a trustworthy mechanic is often that they will outline indicated maintenance and be clear at describing what will improve if service is completed, and what the consequences will be if its not and will outline a best-better-good lineup of options, wherein best is pretty much all recommendable maintenance, better is a good balance given the value and use of the bike, and good restores the bike to safe and rideable condition and/or avoids very expensive costs with inexpensive repairs.

Nine years won't wear out a rim. That raised my BS flag. Rim wear, sure, but age is just a number. I'd check with another shop, mechanic, or a rider whom you trust before I swapped the rim.

Did he show you how the chainring was worn? If you've changed the chains before they get too worn, you may have replaced a cassette or two, and one or more chainring(s) might be worn. If it ain't worn, you don't need to change anything. With the (new/not-stretched) chain on the small or middle ring, try to pull the chain forward and off the ring. If you can see daylight between the chain and the ring, the ring will need to be replaced. If the chain slips on the ring when you put a new chain on, the ring needs to be replaced. Those are the only two diagnostics I know of -- although someone may pipe in with another. If neither of those says "new ring," well, you probably don't need a new ring.

An indicator that the mechanic was not trying to rip you off was that he was suggesting a cheaper tire than the exact replacement. This tells me that he did not know the more expensive ones were in stock, as there are often a pile of tires in the shop that go on repair bikes, and another pile that is kept where customers can see and touch them. There is nothing suspicious about a particular make and model of tire in one of these places and not in the other.

Unless the bike was ridden on wet sandy roads I doubt the rims need to be replaced. Just because you see fine wear marks, they occur shortly after you get the bike.

As an aside the pictures of the worn out rims that have broken go against what riders that dont like disc brakes say.

^my thought. Ask OP's brother what he would do with an aluminum brake rotor...